1. Field of the Invention
The present invention relates to a mobile terminal such as a mobile phone or a personal digital assistant (PDA) and, more particularly, to a mobile terminal designed such that two housings are connected to each other via a connection mechanism rotatable in three-dimensional directions, and are respectively provided with antennas.
2. Description of the Related Art
In general, a radio communication device has a plurality of antennas provided in a housing and performs diversity reception. Many antenna units used for diversity reception each comprise a combination of a rod antenna to be pulled out from the housing, and an inverted F antenna housed in the housing, and the like.
Among recent mobile terminals such as mobile phones and PDAs, apparatuses comprising built-in antennas are the mainstream. Apparatuses having two antennas used for diversity reception, both of which comprise built-in antennas, have been proposed (see, for example, Japanese Patent No. 3112464).
In general, the housing of a mobile terminal such as a mobile phone has a small size. For this reason, if two antennas for diversity reception both comprise built-in antennas, it is difficult to secure a sufficient distance between the antennas. An increasing number of mobile terminals are being designed such that the two housings are rotary connected to each other via a connection mechanism such as a hinge mechanism, and the form of the housings can be changed in accordance with the usage scene. Some of these terminals can obtain good diversity performance in a given form of the housings but cannot obtain required diversity performance in another form of the housings. This problem leads to a very undesirable situation that it is impossible to obtain an expected data transmission rate when transmitting rich contents such as moving images by using a high-speed wireless interface such as a WLAN (Wireless Local Area Network), EVDOrev.A, HSDPA (High Speed Downlink Packet Access), or MIMO (Multiple Input Multiple Output).